Step-by-step explanation:
There are 5 different positions of 666:
666////
/666///
//666//
///666/
////666
The forward dashes represent any number from 0 to 9.
Case 1: "666////"
Number of ways = 10⁴ = 10,000.
Case 2: The other positions.
Since the 1st forward dash cannot be 0 (leading digit),
Number of ways for each position = 9 * 10³ = 9,000
Number of ways for all 4 positions = 9,000 * 4 = 36,000.
Total evil numbers = 10,000 + 36,000 = 46,000.
Answer:
5x² - 10x - 15 = 0
Step-by-step explanation:
Given that the roots are x = 3 and x = - 1, then the factors are
(x - 3) and (x + 1) and the quadratic is the product of the factors, that is
f(x) = a(x - 3)(x + 1) ← a is a multiplier
Here a = 5, thus
f(x) = 5(x - 3)(x + 1) ← expand factors using FOIL
= 5(x² - 2x - 3) ← distribute parenthesis by 5
= 5x² - 10x - 15
Thus equation is
5x² - 10x - 15 = 0
Answer:
x=9,-1 and 
Explanation:
we have been given with the quadratic equation 
we compare the given quadratic equation with general quadratic equation
general quadratic is 
from given quadratic equation a=1,b= -8,c= -9
substituting these values in the formula for discriminant 

Now, to find the value of x
Formula is 
Now, substituting the values we will get

And rewritting the given equation by shifting 9 to right hand side of the given equation and taking minus inside the bracket so as to convert it in the form of

9514 1404 393
Answer:
Step-by-step explanation:
The lateral surface area is the product of half the circumference, and the slant height:
LA = πrh = π(11.4 cm)(23 cm) = 262.2π cm²
The total surface area adds the area of the base to that:
A = πr² +LA = π(11.4 cm)² +262.2π cm² = (129.96 +262.2)π cm²
A = 392.16π cm²
Answer:
d/7 = c
Step-by-step explanation:
-5c+d=2c
Add 5c to each side
-5c+5c+d=2c+5c
d = 7c
Divide each side by 7
d/7 = 7c/7
d/7 = c